It is conventionally known that stereoscopic viewing utilizing parallax can be achieved by combining and displaying a plurality of images. Such an image that allows stereoscopic viewing (which will hereinafter be referred to as “stereoscopic image” or “stereo image”) is generated based on a plurality of images that are obtained by imaging the same subject from different directions and therefore have a parallax therebetween.
Generation of a stereoscopic image in this manner is used not only in the fields of digital cameras and televisions but also in the field of radiographic imaging. Namely, radiation is applied to the subject from different directions, and each radiation transmitted through the subject is detected with a radiographic image detector to obtain a plurality of radiographic images having a parallax therebetween, and a stereoscopic image is generated based on these radiographic images (see, for example, Japanese Unexamined Patent Publication No. 2010-279516). By generating a stereoscopic image in this manner, a radiographic image that provides feel of depth can be observed, which is more suitable for diagnosis.
On the other hand, a tomosynthesis imaging apparatus, wherein a radiation source is moved to apply radiation to the subject from different imaging directions, similarly to a radiographic imaging apparatus for taking the above-described stereoscopic image, has been proposed (see, for example, Japanese Unexamined Patent Publication No. 2010-131170). This tomosynthesis imaging apparatus performs imaging operations with applying radiation to the subject from different imaging directions, as described above, and adds up a plurality of radiographic images obtained by the imaging operations to provide an image where a desired slice plane is emphasized.